1. Field of the Invention
This invention relates to improvements in and concerning a manual cable cutter for cutting various cables, such as wire cables, electric cables, communication lines, and reinforcing bars.
2. Description of the Prior Art
Among the conventional cable cutters of this class is counted the cable cutter which is disclosed in U.S. Pat. No. 5,218,768.
The conventional cable cutter, though not specifically illustrated, is constructed by forming a pair of handles joined mutually in the upper part sides thereof and urged in the expanding direction by the spring action, assigning one of the pair of handles as a fixed handle and the other as a shaking handle, disposing a fixed cutting blade continuously in the upper part of the fixed handle and, at the same time, causing the basal end part of a turning cutting blade having a row of teeth formed on the arcuate outer face thereof to be turnably supported on the leading end part of the fixed cutting blade, disposing rotatably a holdback claw in the upper part of the fixed handle, causing the holdback claw to be meshed by the urging spring pressure with the outer row of teeth of the turning cutting blade, causing a feeding claw to be rotatably supported on the shaking handle, and similarly causing the feeding claw to be meshed by the urging spring pressure with the outer row of teeth of the turning cutting blade.
The actual use of the conventional cable cutter is attained by inserting a cable as a given workpiece into a vacant area formed between the turning cutting blade and the fixed cutting blade when they are opened, then guiding the free end part side of the turning cutting blade in the closing direction around the rotatable support mentioned above as a fulcrum, thereby encircling the periphery of the cable with the turning cutting blade and the fixed cutting blade, and subsequently taking hold of the pair of handles and imparting a closing motion continuously to the shaking handle. Each time the closing motion is imparted to the shaking handle, the turning cutting blade is made to continue an automatic rotational motion until the vacant area mentioned above decreases and reaches zero by the actions of idle slide and push produced by the feeding claw meshed with the outer row of teeth of the turning cutting blade. As a result, the cable is cut by the blade parts formed along the opposed edges of the turning cutting blade and the fixed cutting blade. During the process described above, the holdback claw like the feeding claw prevents the turning cutting blade from rotating reversely owing to the actions of idle slide and push exerted on the outer row of teeth of the turning cutting blade.
The cancellation of the engagement of the feeding claw and the holdback claw with the outer row of teeth of the turning cutting blade is attained by tentatively closing the fixed handle and the shaking handle until parallelism, retaining them in parallelism, and opening the shaking handle meanwhile rotating the holdback claw in the direction of cancelling the engagement thereof with the outer row of teeth against the urging spring pressure. As a result, the action of the holdback claw rotates the feeding claw likewise in the direction of cancelling the engagement thereof with the outer row of teeth. Thus, the turning cutting blade is enabled to be freely turned in the two opposite directions.
The work of cutting a varying metal cable, on account of the efficiency of the cutter and the hardness and diameter of the cable, often encounters such an unexpected accident that the turning cutting blade, in the process of generating a cutting motion, will fail to continue the rotational motion in the closing direction in spite of an ardent effort to impart a closing motion to the shaking handle. The cable cutter of this kind, therefore, requires a construction capable of promptly coping with this trouble, namely a construction capable of reversing the turning cutting blade in the opening direction and allowing easy removal of the cable in trouble.
The conventional cable cutter theoretically ought to answer the requirement because the turning cutting blade is enabled to move backward by cancelling the engagement of the holdback claw and the feeding claw with the outer row of teeth of the turning cutting blade.
In the conventional cable cutter, however, the cancellation of the engagement of the holdback claw and the feeding claw with the outer row of teeth must be preceded by the closure of the fixed handle and the shaking handle until parallelism. When the shaking handle is accidentally frozen in its opened state, the fixed handle and the shaking handle can no longer be closed toward each other. In this case, therefore, the requirement mentioned above cannot be answered because the engagement of the holdback claw and the feeding claw with the outer row of teeth of the turning cutting blade cannot be cancelled.
This invention, having originated in the appreciation of such problems as are encountered by the conventional manual cable cutter, has for a primary object thereof the provision of a novel manual cable cutter which enables the holdback claw and the feeding claw to be simply and infallibly retracted from the outer row of teeth of the turning cutting blade.